Is synergy the key to overcoming antibiotic resistance?

The latest research from the European Molecular Biology Laboratory (EMBL) and collaborators in Nature have demonstrated that certain combinations of antibiotics, alongside other adjuvants such as food additives or non-antibiotic drugs are more likely to combat antibiotic resistance.

The team, led by Nassos Typas at EMBL Heidelberg (Heidelberg, Germany), conducted the first large-scale screening of its kind, screening the effect of almost 3000 drug combinations on three different disease-causing species of bacteria.

Although many of the investigated combinations actually stopped the antibiotics from working to their full potential, there were over 500 drug combinations that enhanced the antibiotic potency, even when tested on multi-drug resistant strains isolated from hospital patients.

Of particular interest was the ability of vanillin – the compound that gives vanilla its distinctive smell – to increase the antibiotic potential of spectinomycin, an antibiotic originally developed for the treatment of gonorrhea in the 1960s.

Spectinomycin is rarely utilized nowadays due to the resistance developed against it, however, Ana Brochado (EMBL), the first author of the paper explains that: “of the combinations tested, this was one of the most effective and promising synergies we identified”.

Interestingly, vanillin had an opposing effect on most other antibiotics, working in a similar way to aspirin to decrease activity; however, its effects in human cells have not yet been tested.

Nassos Typas went on to explain the beneficial effects of drug combinations that lower the potency of an antibiotic: “Antibiotics can lead to collateral damage and side effects because they target healthy bacteria as well. But the effects of these drug combinations are highly selective, and often only affect a few bacterial species.”

He continued: “In the future, we could use drug combinations to selectively prevent the harmful effects of antibiotics on healthy bacteria. This would also decrease antibiotic resistance development, as healthy bacteria would not be put under pressure to evolve antibiotic resistance, which can later be transferred to dangerous bacteria.”